[Qemu-devel] [PULL 18/27] block/qcow: use buffer-based io

[Kevin Wolf <kwolf@redhat.com>]

From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 block/qcow.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/block/qcow.c b/block/qcow.c
index 10d2cf14b3..1bb8fd05e2 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -631,7 +631,6 @@ static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, uint64_t offset,
     int offset_in_cluster;
     int ret = 0, n;
     uint64_t cluster_offset;
-    QEMUIOVector hd_qiov;
     uint8_t *buf;
     void *orig_buf;
 
@@ -663,11 +662,10 @@ static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, uint64_t offset,
         if (!cluster_offset) {
             if (bs->backing) {
                 /* read from the base image */
-                qemu_iovec_init_buf(&hd_qiov, buf, n);
                 qemu_co_mutex_unlock(&s->lock);
                 /* qcow2 emits this on bs->file instead of bs->backing */
                 BLKDBG_EVENT(bs->file, BLKDBG_READ_BACKING_AIO);
-                ret = bdrv_co_preadv(bs->backing, offset, n, &hd_qiov, 0);
+                ret = bdrv_co_pread(bs->backing, offset, n, buf, 0);
                 qemu_co_mutex_lock(&s->lock);
                 if (ret < 0) {
                     break;
@@ -688,11 +686,10 @@ static coroutine_fn int qcow_co_preadv(BlockDriverState *bs, uint64_t offset,
                 ret = -EIO;
                 break;
             }
-            qemu_iovec_init_buf(&hd_qiov, buf, n);
             qemu_co_mutex_unlock(&s->lock);
             BLKDBG_EVENT(bs->file, BLKDBG_READ_AIO);
-            ret = bdrv_co_preadv(bs->file, cluster_offset + offset_in_cluster,
-                                 n, &hd_qiov, 0);
+            ret = bdrv_co_pread(bs->file, cluster_offset + offset_in_cluster,
+                                n, buf, 0);
             qemu_co_mutex_lock(&s->lock);
             if (ret < 0) {
                 break;
@@ -731,7 +728,6 @@ static coroutine_fn int qcow_co_pwritev(BlockDriverState *bs, uint64_t offset,
     int offset_in_cluster;
     uint64_t cluster_offset;
     int ret = 0, n;
-    QEMUIOVector hd_qiov;
     uint8_t *buf;
     void *orig_buf;
 
@@ -776,11 +772,10 @@ static coroutine_fn int qcow_co_pwritev(BlockDriverState *bs, uint64_t offset,
             }
         }
 
-        qemu_iovec_init_buf(&hd_qiov, buf, n);
         qemu_co_mutex_unlock(&s->lock);
         BLKDBG_EVENT(bs->file, BLKDBG_WRITE_AIO);
-        ret = bdrv_co_pwritev(bs->file, cluster_offset + offset_in_cluster,
-                              n, &hd_qiov, 0);
+        ret = bdrv_co_pwrite(bs->file, cluster_offset + offset_in_cluster,
+                             n, buf, 0);
         qemu_co_mutex_lock(&s->lock);
         if (ret < 0) {
             break;
@@ -1056,7 +1051,6 @@ qcow_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
                            uint64_t bytes, QEMUIOVector *qiov)
 {
     BDRVQcowState *s = bs->opaque;
-    QEMUIOVector hd_qiov;
     z_stream strm;
     int ret, out_len;
     uint8_t *buf, *out_buf;
@@ -1122,9 +1116,8 @@ qcow_co_pwritev_compressed(BlockDriverState *bs, uint64_t offset,
     }
     cluster_offset &= s->cluster_offset_mask;
 
-    qemu_iovec_init_buf(&hd_qiov, out_buf, out_len);
     BLKDBG_EVENT(bs->file, BLKDBG_WRITE_COMPRESSED);
-    ret = bdrv_co_pwritev(bs->file, cluster_offset, out_len, &hd_qiov, 0);
+    ret = bdrv_co_pwrite(bs->file, cluster_offset, out_len, out_buf, 0);
     if (ret < 0) {
         goto fail;
     }
-- 
2.20.1